Colorado frost dates
The typical last spring frost ranges from Apr 30 in Pueblo to Jun 21 in Vail.
20 of the 20 Colorado cities listed have typical frost dates. The longest frost-free season is 161 days in Pueblo; the shortest is 77 days in Vail. For a single address, look up your ZIP code: rural ZIPs use their nearest suitable station.
| City | Last spring frost | 1 in 10 after | First fall frost | 1 in 10 before | Hard freeze (28°F) | Season |
|---|---|---|---|---|---|---|
| Arvada | May 5 | May 18 | Oct 5 | Sep 20 | Apr 25 / Oct 14 | 151 days |
| Aspen | May 31 | Jun 14 | Sep 23 | Sep 11 | May 13 / Oct 2 | 114 days |
| Aurora | May 4 | May 16 | Oct 8 | Sep 25 | Apr 22 / Oct 18 | 156 days |
| Boulder | May 6 | May 18 | Oct 5 | Sep 21 | Apr 27 / Oct 15 | 151 days |
| Breckenridge | Jun 6 | Jun 21 | Sep 19 | Sep 5 | May 25 / Sep 26 | 103 days |
| Centennial | May 5 | May 17 | Oct 8 | Sep 25 | Apr 25 / Oct 17 | 154 days |
| Colorado Springs | May 3 | May 15 | Oct 8 | Sep 26 | Apr 24 / Oct 16 | 158 days |
| Denver | May 4 | May 16 | Oct 8 | Sep 25 | Apr 22 / Oct 18 | 156 days |
| Estes Park | May 30 | Jun 14 | Sep 17 | Sep 3 | May 16 / Sep 28 | 109 days |
| Fort Collins | May 2 | May 14 | Oct 7 | Sep 24 | Apr 20 / Oct 17 | 157 days |
| Greeley | May 2 | May 14 | Oct 8 | Sep 26 | Apr 20 / Oct 18 | 159 days |
| Highlands Ranch | May 5 | May 17 | Oct 8 | Sep 25 | Apr 25 / Oct 17 | 154 days |
| Lakewood | May 5 | May 18 | Oct 5 | Sep 20 | Apr 25 / Oct 14 | 151 days |
| Longmont | May 7 | May 22 | Oct 5 | Sep 23 | Apr 28 / Oct 12 | 151 days |
| Pueblo | Apr 30 | May 12 | Oct 9 | Sep 27 | Apr 19 / Oct 18 | 161 days |
| Steamboat Springs | Jun 9 | Jun 24 | Sep 12 | Aug 31 | May 20 / Sep 23 | 93 days |
| Telluride | May 17 | Jun 3 | Oct 1 | Sep 19 | May 2 / Oct 11 | 137 days |
| Thornton | May 2 | May 14 | Oct 11 | Sep 26 | Apr 20 / Oct 21 | 160 days |
| Vail | Jun 21 | Jul 9 | Sep 7 | Aug 26 | May 31 / Sep 21 | 77 days |
| Westminster | May 2 | May 14 | Oct 11 | Sep 26 | Apr 20 / Oct 21 | 160 days |
Reading the table: Highlands Ranch
In Highlands Ranch, the last spring frost typically comes around May 5: in half of years it is earlier, in half later. In 1 year in 10 it comes after May 17, 12 days later, so tender plants set out after that date have a 90% chance of escaping frost. In fall, the first frost typically arrives around Oct 8, and in 1 year in 10 before Sep 25. Hard freezes (28°F) usually end earlier in spring and start later in fall: around Apr 25 and Oct 17 in Highlands Ranch.
Frost dates at more Colorado weather stations
NOAA stations across Colorado used by our ZIP code lookup, named for the town they are in.
| Station | Elevation | Last spring frost | First fall frost |
|---|---|---|---|
| Akron Washington Co Airport | 4,663 ft | May 6 (1 in 10 after May 19) | Oct 8 (before Sep 27) |
| Alamosa San Luis Airport | 7,533 ft | Jun 7 (1 in 10 after Jun 24) | Sep 15 (before Sep 4) |
| Allenspark 3NW | 8,500 ft | Jun 14 (1 in 10 after Jun 28) | Sep 12 (before Aug 25) |
| Bailey | 7,752 ft | Jun 16 (1 in 10 after Jul 1) | Sep 8 (before Aug 27) |
| Black Canyon Of The Gunnison | 8,151 ft | May 23 (1 in 10 after Jun 9) | Oct 1 (before Sep 20) |
| Boulder 14 W | 9,828 ft | Jun 21 (1 in 10 after Jul 4) | Sep 2 (before Aug 17) |
| Briggsdale | 4,862 ft | May 12 (1 in 10 after May 25) | Sep 28 (before Sep 15) |
| Brighton 3 Se | 5,016 ft | May 3 (1 in 10 after May 16) | Oct 7 (before Sep 26) |
| Buena Vista 2S | 7,954 ft | May 27 (1 in 10 after Jun 11) | Sep 23 (before Sep 10) |
| Burlington | 4,162 ft | May 6 (1 in 10 after May 19) | Oct 9 (before Sep 27) |
| Byers 5 Ene | 5,101 ft | May 13 (1 in 10 after May 30) | Oct 2 (before Sep 20) |
| Canon City | 5,378 ft | May 4 (1 in 10 after May 18) | Oct 7 (before Sep 25) |
| Castle Rock | 6,185 ft | May 9 (1 in 10 after May 24) | Oct 2 (before Sep 17) |
| Cedaredge 3E | 6,838 ft | May 3 (1 in 10 after May 21) | Oct 9 (before Sep 27) |
| Cheyenne Wells 2NE | 4,203 ft | May 1 (1 in 10 after May 17) | Oct 14 (before Oct 1) |
| Coal Creek Canyon | 8,950 ft | Jun 5 (1 in 10 after Jun 19) | Sep 16 (before Sep 2) |
| Cochetopa Creek | 8,006 ft | Jun 21 (1 in 10 after Jul 7) | Sep 5 (before Aug 21) |
| Cortez | 6,167 ft | May 12 (1 in 10 after May 31) | Oct 7 (before Sep 26) |
| Craig 4SW | 6,496 ft | May 29 (1 in 10 after Jun 13) | Sep 20 (before Sep 5) |
| Crestone 2 Se | 8,004 ft | May 26 (1 in 10 after Jun 9) | Sep 26 (before Sep 14) |
| Cripple Creek 3NNW | 9,235 ft | May 26 (1 in 10 after Jun 9) | Sep 26 (before Sep 13) |
| Crook | 3,709 ft | May 11 (1 in 10 after May 23) | Oct 4 (before Sep 23) |
| Del Norte 3ENE | 7,845 ft | May 23 (1 in 10 after Jun 8) | Sep 25 (before Sep 13) |
| Durango La Plata Co Airport | 6,660 ft | Jun 1 (1 in 10 after Jun 15) | Sep 27 (before Sep 15) |
| Eads | 4,212 ft | Apr 30 (1 in 10 after May 12) | Oct 13 (before Oct 1) |
| Elizabeth 2NW | 6,611 ft | May 16 (1 in 10 after Jun 1) | Oct 2 (before Sep 18) |
| Evergreen | 6,985 ft | May 23 (1 in 10 after Jun 10) | Sep 22 (before Sep 6) |
| Fairplay S Park Rd | 9,995 ft | Jun 16 (1 in 10 after Jun 30) | Sep 9 (before Aug 21) |
| Flagler 1S | 4,921 ft | May 5 (1 in 10 after May 20) | Oct 8 (before Sep 27) |
| Ft Collins 4 E | 4,920 ft | May 3 (1 in 10 after May 15) | Oct 6 (before Sep 22) |
| Ft Morgan | 4,376 ft | May 6 (1 in 10 after May 19) | Oct 6 (before Sep 24) |
| Georgetown | 8,520 ft | May 30 (1 in 10 after Jun 14) | Sep 19 (before Sep 5) |
| Grand Junction Walker Fld | 4,858 ft | Apr 28 (1 in 10 after May 14) | Oct 16 (before Oct 3) |
| Grand Lake 6 Ssw | 8,288 ft | Jun 13 (1 in 10 after Jun 28) | Sep 7 (before Aug 21) |
| Grant | 8,675 ft | Jun 15 (1 in 10 after Jun 30) | Sep 9 (before Aug 26) |
| Gross Rsvr | 7,970 ft | May 24 (1 in 10 after Jun 10) | Sep 23 (before Sep 9) |
| Holly | 3,401 ft | May 1 (1 in 10 after May 14) | Oct 12 (before Sep 29) |
| Holyoke | 3,780 ft | May 11 (1 in 10 after May 23) | Oct 3 (before Sep 20) |
| Idalia | 3,965 ft | May 4 (1 in 10 after May 17) | Oct 9 (before Sep 24) |
| Ignacio 6ESE | 6,548 ft | May 23 (1 in 10 after Jun 7) | Sep 29 (before Sep 18) |
| Joes | 4,275 ft | May 3 (1 in 10 after May 15) | Oct 9 (before Sep 29) |
| John Martin Dam | 3,814 ft | Apr 24 (1 in 10 after May 8) | Oct 15 (before Oct 2) |
| Kassler | 5,587 ft | May 8 (1 in 10 after May 22) | Oct 3 (before Sep 21) |
| Lake City | 8,667 ft | Jun 8 (1 in 10 after Jun 24) | Sep 17 (before Sep 6) |
| Lake George 8 Sw | 8,550 ft | Jun 2 (1 in 10 after Jun 17) | Sep 19 (before Sep 6) |
| Limon Wsmo | 5,364 ft | May 21 (1 in 10 after Jun 4) | Sep 26 (before Sep 14) |
| Lindon 5 Wnw | 4,851 ft | May 15 (1 in 10 after May 30) | Oct 2 (before Sep 20) |
| Manassa | 7,695 ft | May 28 (1 in 10 after Jun 11) | Sep 21 (before Sep 9) |
| Matheson 8 Se | 5,830 ft | May 12 (1 in 10 after May 26) | Oct 2 (before Sep 19) |
| Monument | 7,080 ft | May 14 (1 in 10 after May 31) | Oct 1 (before Sep 16) |
| New Raymer | 4,783 ft | May 9 (1 in 10 after May 22) | Oct 4 (before Sep 21) |
| Norwood | 7,020 ft | May 25 (1 in 10 after Jun 13) | Oct 1 (before Sep 14) |
| Nunn 7 Nne | 5,390 ft | May 13 (1 in 10 after May 27) | Sep 27 (before Sep 14) |
| Ordway 1 Ene | 4,312 ft | May 2 (1 in 10 after May 14) | Oct 8 (before Sep 25) |
| Rye 1SW | 7,141 ft | May 5 (1 in 10 after May 20) | Oct 10 (before Sep 27) |
| Sterling | 3,974 ft | Apr 30 (1 in 10 after May 12) | Oct 9 (before Sep 28) |
| Walsenburg 1 Nw | 6,292 ft | May 6 (1 in 10 after May 20) | Oct 4 (before Sep 23) |
| Walsh 1 W | 3,978 ft | Apr 30 (1 in 10 after May 12) | Oct 14 (before Oct 1) |
| Westcliffe | 7,873 ft | Jun 11 (1 in 10 after Jun 28) | Sep 9 (before Aug 28) |
| Yampa | 7,857 ft | Jun 14 (1 in 10 after Jun 28) | Sep 11 (before Aug 29) |
32°F dates from NOAA 1991-2020 freeze probabilities for each city's station. "1 in 10 after": a 10% chance of a later spring frost (planting is 90% safe after it). How to read frost dates.